1. Field of Invention
The present invention relates to keys and keyboards for data entry and device control.
2. Description of Prior Art
Increasingly higher-density integrated circuits enable computers and other electronic devices o be continuingly reduced in size. Although conventional data entry devices such as keys and keyboards can be scaled down in physical dimensions, a high practical limit to such reduction is imposed by their design and construction. For customary alphanumeric data entry in the English-speaking world, in addition to the usual 10 numerals, there needs to be included the 26 alphabets plus a certain number of punctuation and functional keys. The assignment of every such alphabet, numeral or function to a unique key results in a relatively large conventional computer keyboard. The use of much smaller keys to significantly reduce the size of conventional keyboard would only make the keyboard difficult to use and error-prone. This problem represents a major obstacle to continued miniaturization of electronic goods that use conventional keyboards.
Prior art teaches multiple schemes that attempt to address this problem. For instance, in the conventional touch tone telephone, alphabets and numerals are assigned within twelve keys. Each key carries up to three alphabets and a numeral. To distinguishably identify a character or a numeral, an elaborate scheme needs to be used. One such scheme is disclosed in U.S. Pat. No. 4,918,721 to Hashimoto, Apr. 17, 1990. Another scheme is disclosed in U.S. Pat. No. 4,825,464 to Wen, Apr. 25, 1989.
In both the Hashimoto and Wen patents, a unique sequence of key strokes is required to identify a single alphabet. The disadvantages of those schemes are multi-fold. First, those schemes are difficult and time-consuming to learn and use since multiple cumbersome and error-prone steps are involved. Second, once those decoding schemes are learned, they need to be accurately memorized. Third, infrequent usage may pose recall difficulties Fourth, during an emergency, inability to accurately recall the stroke sequence for each alphabet will produce errors and delays that may cause grave consequences Finally there is no standard among the different schemes, which appear to be totally arbitrary. Not surprisingly, there is no general acceptance of any such schemes as a standard.
Disclosed in U.S. Pat. No. 4,065,650 to Lou, Dec. 27, 1977 is a keyboard design with a grouping of sideways-actuated keys for use in a calculator and does not allow alphabet entry.
Keyboards with multi-directional keys were taught in U.S. Pat. No. 4,769,516 to Allen, Sep. 6, 1988 and in U.S. Pat. No. 4,029,915 to Ojima, Jun. 14, 1977. In Allen's invention, each key can only generate up to 3 alphanumerics. The user needs to exercise his or her fingers in different directions, namely extending, flexing, or depressing vertically in order to actuate the key. Moreover, the internal construction of each key comprises quite a number of components and is relatively complicated. In Ojima's patent, multi-directional numeric and multi-function keys are implemented in a row to be used as a calculator keypad disposed on a pen.
Disclosed in U.S. Pat. No. 4,687,200 to Shirai, Aug. 18, 1987 is a multi-directional sustained-on switch for use in a game playing apparatus. There were no considerations for maximum compactness or functionality for use as an alphanumeric key, nor were there provisions for an optional downward compression, or for encoding to form symbols in the ASCII or other standard code.
Disclosed in U.S. Pat. No. 4,896,003 to Hsieh, Jan. 23, 1990 is a multi-position electrical switch, utilizing a cylindrical pushbutton actuating member, and designed to reduce friction and wear. Again, there were no considerations for maximum compactness or functionality for use as an alphanumeric key, nor were there provisions for an optional downward compression, or for encoding to form symbols in the ASCII or other standard code.
None of the aforementioned patents discloses a functional keyboard that is compact in size, would not cause overstriking of neighboring keys during data entry, and able to address all the alphanumerics plus special operation functions.